Coal-based solid waste composite material and application thereof and soil remediation method

Abstract

The application provides a coal-based solid waste composite material and application thereof, and belongs to the technical field of soil remediation. The coal-based solid waste composite material is successfully obtained by using 400-600 parts of desulfurization gypsum, 100-300 parts of fly ash, 100-300 parts of wood fiber, 80-120 parts of humic acid, 10-30 parts of sodium silicate, 8-12 parts of EDTA, 8-12 parts of citric acid and 10-30 parts of hydroxyapatite, and the coal-based solid waste composite material solves the problem that the soil remediation agent in the prior art cannot solve the high-concentration heavy metal composite pollution, and improves the remediation effect. The coal-based solid waste composite material and the soil remediation method can effectively reduce the release amount of various high-concentration heavy metals in the polluted soil, do not affect the properties of the soil itself, can be used for subsequent crop cultivation, realize long-term remediation of the soil, and have wide application value and development potential.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil remediation, and particularly relates to a coal-based solid waste composite material and application thereof and a soil remediation method. BACKGROUND

[0002] Soil, as an indispensable non-renewable resource for human beings, is the material basis for human survival. In recent decades, with the rapid growth of global population, energy development, industrial construction and urbanization have also developed at an alarming rate. Global industrialization has led to the discharge of a large number of potentially toxic compounds into the environment, including heavy metals. According to statistics, in the past 50 years, the global discharge of Cd into the environment reached 220,000 tons, Cu 939,000 tons, Pb 783,000 tons and Zn 1,350,000 tons, of which a considerable part directly or indirectly entered the soil environment, thereby polluting the soil environment in some areas, thus destroying the normal functions of the local ecosystem and causing harm to human health. At the same time, heavy metal pollution has the characteristics of long incubation period, great harm and difficulty in being detected by people. Once pollution by heavy metals is formed, it is not easy to remove from the environment, and has strong stubbornness, so heavy metals are often listed by people as one of the types of pollutants that need to be prioritized for treatment. Soil heavy metal pollution produced by various industrial enterprises is more long-term and hidden. The accumulation of heavy metals in farmland around the enterprises not only reduces the yield and quality of agricultural products, but also may act on the surface and groundwater of the pollution area through runoff and leaching, causing deterioration of the entire regional ecological environment and ultimately endangering human health.

[0003] Soil remediation is based on the traditional soil chemistry branch scientific system, and draws on the theoretical basis, methods and technologies of soil ecology, soil chemistry, agricultural chemistry, plant nutrition, environmental chemistry, environmental engineering and other related disciplines. It has gradually developed into a branch discipline of soil, with the core research contents of pollution area, pollution characteristics, pollution risk prediction and assessment, soil pollution control and remediation technology research and development, comprehensive management and biological resource disposal.

[0004] Heavy metal refers to a large class of elements with important significance in industrial production and biological effects, generally refers to the specific gravity greater than 4.0, and the commonly used, toxic to biological elements, such as Hg, Cd, Pb, As and Cr. The heavy metals in the environment have some significant common behavior characteristics, which are different from organic compounds, and the repair mechanism and technology of heavy metal contaminated soil also have significant characteristics. Soil heavy metal pollution refers to the process that the amount of heavy metal entering the soil due to human activities exceeds the content of heavy metal in the soil and the environmental capacity of the soil, thereby causing changes in soil composition and physicochemical properties. When the soil ecological balance is destroyed, the soil natural function and soil quality will deteriorate. The main ways of heavy metal contaminated soil are two kinds of irrigation of waste water containing pollutants and natural settlement of heavy metal dust. Soil heavy metal not only harms human health through food chain such as agricultural products and groundwater, but also has the characteristics of stable fixation with soil and difficult migration, thereby showing the accumulation and strong regional pollution of pollution.

[0005] The heavy metal contaminated soil is often repaired by physical, chemical and biological techniques, and good results can be often obtained.

[0006] The Chinese patent CN109020748A discloses a heavy metal soil repair agent composed of bird droppings, bone meal and apatite. The soil repair agent can improve the pH value of soil, passivate heavy metal, reduce the activity of heavy metal, and improve the production capacity of soil. The preparation method of the soil repair agent is simple, the preparation cost is low, and the soil repair agent has high popularization and application value.

[0007] The Chinese patent CN106221701A discloses a heavy metal soil repair agent, which is composed of the following raw materials in parts by weight: activated carbon fiber 15-25 parts; amino polycarboxylic acid 5-12 parts; organic acid 5-10 parts; organic matter 3-10 parts; biological emulsifier 2-8 parts; and sodium lignosulfonate 1-5 parts. The soil repair agent has reasonable formula, simple preparation method, can effectively reduce various heavy metal pollutants in soil, improve the permeability of soil air, and improve the growth environment of crops, is environment-friendly and green.

[0008] However, the soil repair agent in the above prior art cannot realize the repair of heavy metal pollution with high concentration, and the repair effect needs to be improved. SUMMARY

[0009] The purpose of the present application is to provide a coal-based solid waste composite material and its application, and a soil heavy metal pollution repair method based on a large amount of basic research in the early stage, which has excellent repair efficacy.

[0010] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical solutions:

[0011] The application provides a coal-based solid waste composite material, which comprises the following components in parts by weight:

[0012] Desulfurization gypsum 400-600 parts, fly ash 100-300 parts, wood fiber 100-300 parts, humic acid 80-120 parts, sodium silicate 10-30 parts, EDTA 8-12 parts, citric acid 8-12 parts and hydroxyapatite 10-30 parts.

[0013] Preferably, the coal-based solid waste composite material comprises the following components in parts by weight:

[0014] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts.

[0015] Preferably, the coal-based solid waste composite material further comprises a microbial agent.

[0016] Preferably, the coal-based solid waste composite material further comprises a microbial agent.

[0017] Preferably, the coal-based solid waste composite material further comprises a microbial agent.

[0018] Preferably, the coal-based solid waste composite material further comprises a microbial agent.

[0019] Preferably, the coal-based solid waste composite material further comprises a microbial agent. 7 ~ 10 10 CFU / mL.

[0020] The application further provides application of the coal-based solid waste composite material in remediation of heavy metal contaminated soil.

[0021] The application further provides a soil remediation method, which comprises the following steps:

[0022] Mixing the coal-based solid waste composite material with uncontaminated soil to obtain a remediation substrate;

[0023] Mixing the remediation substrate with heavy metal contaminated soil to be remediated to perform soil passivation remediation.

[0024] Preferably, the coal-based solid waste composite material and the uncontaminated soil are mixed at a weight ratio of 1:50-150.

[0025] The remediation substrate and the heavy metal contaminated soil to be remediated are mixed at a weight ratio of 1:10-50.

[0026] The application has the following technical effects and advantages:

[0027] The coal-based solid waste composite material is successfully obtained by adopting desulfurization gypsum 400-600 parts, fly ash 100-300 parts, wood fiber 100-300 parts, humic acid 80-120 parts, sodium silicate 10-30 parts, EDTA 8-12 parts, citric acid 8-12 parts and hydroxyapatite 10-30 parts, can effectively reduce the content of various high-concentration heavy metals in the polluted soil, does not affect the nature of the soil itself, can be used for subsequent crop cultivation, realizes long-term repair of the soil, and has wide application value and development potential. DETAILED DESCRIPTION

[0028] The coal-based solid waste composite material provided by the application comprises the following components in parts by weight:

[0029] Desulfurization gypsum 400-600 parts, fly ash 100-300 parts, wood fiber 100-300 parts, humic acid 80-120 parts, sodium silicate 10-30 parts, EDTA 8-12 parts, citric acid 8-12 parts and hydroxyapatite 10-30 parts; preferably, the coal-based solid waste composite material comprises the following components in parts by weight: desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts.

[0030] In the application, preferably, the coal-based solid waste composite material further comprises a microbial agent; preferably, the weight of the microbial agent in the coal-based solid waste composite material is 50 parts; preferably, the microbial agent contains Paenibacillus mucilaginosus; preferably, the viable bacterial concentration of Paenibacillus mucilaginosus in the microbial agent is 10 7 ~ 10 10 CFU / mL.

[0031] The application also provides application of the coal-based solid waste composite material in heavy metal contaminated soil repair; the soil heavy metal pollution mainly includes the following sources:

[0032] (1) Heavy metal particles in the atmosphere settle

[0033] The heavy metals in the atmosphere mainly come from industrial and metallurgical industrial production, vehicle exhaust emission produces waste gas containing metal dust, and are mainly distributed in the periphery of metallurgical industrial enterprises, highway and railway lines and other regions. Through natural sedimentation or precipitation into the soil environment, mainly distributed in the periphery of industrial and metallurgical enterprises in the urban fringe, the concentration decreases with the diffusion from the city to the countryside.

[0034] (2) Sewage irrigation

[0035] Urban sewage is treated by sewage treatment plant, and then is used to irrigate farmland, grassland or forest land through ditches, realizing sewage irrigation. In some areas, industrial wastewater is mixed with domestic sewage, and a large amount of heavy metal ions are directly leached into the soil environment without treatment for a long time, resulting in soil heavy metal pollution. In the last century, heavy metal pollution has been quite serious in northern China due to long-term sewage irrigation.

[0036] (3) Accumulation of solid waste containing heavy metals

[0037] Tailings produced in mining and smelting enterprises are the main source of mine solid waste. After the rough ore is treated by flotation and dressing in the mine plant, a large amount of dressing reagent remains in the tailings, and the tailings containing heavy metals are accumulated in the tailings dam. When it rains, the heavy metals in the tailings will enter the surrounding soil layer through surface runoff or seep into the underground due to leaching, polluting the groundwater.

[0038] (4) Application of fertilizers and plastic films

[0039] Long-term use of pesticides containing heavy metals Pb, Cd, Hg and As and overuse of fertilizers can lead to excessive content of heavy metals in farmland soil. Among commonly used fertilizers, phosphorus fertilizer contains more heavy metals, and nitrogen fertilizer and potassium fertilizer contain relatively less heavy metals. The content of Cd in phosphorus fertilizer and other compound fertilizers reaches 400 mg / kg. Long-term overuse of fertilizers will cause accumulation of heavy metals in soil, resulting in heavy metal pollution. The plastic film used in agricultural greenhouse contains Cd and Pb heat stabilizers. When the plastic film is left in the farmland soil without reasonable recycling, it will cause soil heavy metal pollution.

[0040] The application also provides a soil remediation method, which comprises the following steps: mixing the coal-based solid waste composite material with uncontaminated soil to obtain a remediation substrate; mixing the remediation substrate with heavy metal contaminated soil to be remediated to perform soil remediation; preferably, the weight ratio of the coal-based solid waste composite material to uncontaminated soil is 1:50-150; and the weight ratio of the remediation substrate to heavy metal contaminated soil to be remediated is 1:10-50.

[0041] The technical solutions provided by the application will be described in detail in combination with examples, but they should not be understood as limitations on the protection scope of the application.

[0042] Example 1

[0043] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like bacillus paste is added, the live bacteria concentration of the jelly-like bacillus paste is 10 8CFU / mL, which is a coal-based solid waste composite material.

[0044] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for heavy metal contaminated soil remediation.

[0045] Example 2

[0046] Desulfurization gypsum 400 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 200 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like bacillus subtilis liquid is added, and the live bacteria concentration of the jelly-like bacillus subtilis liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0047] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for heavy metal contaminated soil remediation.

[0048] Example 3

[0049] Desulfurization gypsum 600 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like bacillus subtilis liquid is added, and the live bacteria concentration of the jelly-like bacillus subtilis liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0050] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for heavy metal contaminated soil remediation.

[0051] Example 4

[0052] Desulfurization gypsum 500 parts, fly ash 100 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like bacillus subtilis liquid is added, and the live bacteria concentration of the jelly-like bacillus subtilis liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0053] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for heavy metal contaminated soil remediation.

[0054] Example 5

[0055] Desulfurization gypsum 500 parts, fly ash 300 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like bacillus subtilis liquid is added, and the live bacteria concentration of the jelly-like bacillus subtilis liquid used is 108 CFU / mL, which is a coal-based solid waste composite material.

[0056] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for heavy metal contaminated soil remediation.

[0057] Example 6

[0058] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 100 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like bacillus paste is added, and the live bacteria concentration of the jelly-like bacillus paste used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0059] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for heavy metal contaminated soil remediation.

[0060] Example 7

[0061] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 300 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like bacillus paste is added, and the live bacteria concentration of the jelly-like bacillus paste used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0062] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for heavy metal contaminated soil remediation.

[0063] Example 8

[0064] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 80 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like bacillus paste is added, and the live bacteria concentration of the jelly-like bacillus paste used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0065] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for heavy metal contaminated soil remediation.

[0066] Example 9

[0067] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 120 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like Paenibacillus liquid is added, the active bacteria concentration of the jelly-like Paenibacillus liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0068] The obtained coal-based solid waste composite material is mixed into 100 times weight of soil for heavy metal contaminated soil remediation.

[0069] Example 10

[0070] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 15 parts, EDTA 12 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like Paenibacillus liquid is added, the active bacteria concentration of the jelly-like Paenibacillus liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0071] The obtained coal-based solid waste composite material is mixed into 100 times weight of soil for heavy metal contaminated soil remediation.

[0072] Example 11

[0073] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 25 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like Paenibacillus liquid is added, the active bacteria concentration of the jelly-like Paenibacillus liquid used is 10 9 CFU / mL, which is a coal-based solid waste composite material.

[0074] The obtained coal-based solid waste composite material is mixed into 100 times weight of soil for heavy metal contaminated soil remediation.

[0075] Example 12

[0076] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 12 parts, citric acid 12 parts and hydroxyapatite 25 parts are mixed, 50 parts of jelly-like Paenibacillus liquid is added, the active bacteria concentration of the jelly-like Paenibacillus liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0077] The obtained coal-based solid waste composite material is mixed into 100 times weight of soil for heavy metal contaminated soil remediation.

[0078] Example 13

[0079] Desulfurized gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 8 parts, citric acid 12 parts and hydroxyapatite 25 parts were mixed, and 50 parts of the jelly-like Paenibacillus liquid was added. The active bacteria concentration of the jelly-like Paenibacillus liquid used was 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0080] The obtained coal-based solid waste composite material was mixed into 100 times the weight of soil for the remediation of heavy metal contaminated soil.

[0081] Example 14

[0082] Desulfurized gypsum 600 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 12 parts and hydroxyapatite 20 parts were mixed, and 40 parts of the jelly-like Paenibacillus liquid was added. The active bacteria concentration of the jelly-like Paenibacillus liquid used was 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0083] The obtained coal-based solid waste composite material was mixed into 120 times the weight of soil for the remediation of heavy metal contaminated soil.

[0084] Example 15

[0085] Desulfurized gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts were mixed, and 60 parts of the jelly-like Paenibacillus liquid was added. The active bacteria concentration of the jelly-like Paenibacillus liquid used was 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0086] The obtained coal-based solid waste composite material was mixed into 100 times the weight of soil for the remediation of heavy metal contaminated soil.

[0087] Comparative Example 1

[0088] Desulfurized gypsum 500 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts were mixed, and 50 parts of the jelly-like Paenibacillus liquid was added. The active bacteria concentration of the jelly-like Paenibacillus liquid used was 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0089] The obtained coal-based solid waste composite material was mixed into 100 times the weight of soil for the remediation of heavy metal contaminated soil.

[0090] Comparative Example 2

[0091] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, and hydroxyapatite 20 parts are mixed, 50 parts of jelly-like Paenibacillus liquid is added, the live bacteria concentration of the jelly-like Paenibacillus liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0092] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil, for use in heavy metal contaminated soil remediation.

[0093] Comparative Example 3

[0094] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts, and hydroxyapatite 20 parts are mixed, 50 parts of Bacillus megaterium liquid is added, the live bacteria concentration of the Bacillus megaterium liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0095] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil, for use in heavy metal contaminated soil remediation.

[0096] Comparative Example 4

[0097] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts, and hydroxyapatite 20 parts are mixed, which is a coal-based solid waste composite material.

[0098] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil, for use in heavy metal contaminated soil remediation.

[0099] Comparative Example 5

[0100] Desulfurization gypsum 100 parts, fly ash 200 parts, wood fiber 300 parts, humic acid 200 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts, and hydroxyapatite 100 parts are mixed, 50 parts of jelly-like Paenibacillus liquid is added, the live bacteria concentration of the jelly-like Paenibacillus liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0101] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil, for use in heavy metal contaminated soil remediation.

[0102] Comparative Example 6

[0103] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 10 parts of Jell-like Paenibacillus liquid is added, the viable bacterial concentration of the Jell-like Paenibacillus liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0104] The obtained coal-based solid waste composite material is mixed into 100 times weight of soil for heavy metal contaminated soil remediation.

[0105] Comparative Example 7

[0106] Desulfurization gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts are mixed, 100 parts of Jell-like Paenibacillus liquid is added, the viable bacterial concentration of the Jell-like Paenibacillus liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0107] The obtained coal-based solid waste composite material is mixed into 100 times weight of soil for heavy metal contaminated soil remediation.

[0108] Comparative Example 8

[0109] Desulfurization gypsum 500 parts is added with 50 parts of Jell-like Paenibacillus liquid, the viable bacterial concentration of the Jell-like Paenibacillus liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0110] The obtained coal-based solid waste composite material is mixed into 100 times weight of soil for heavy metal contaminated soil remediation.

[0111] Comparative Example 9

[0112] Desulfurization gypsum 500 parts, fly ash 200 parts and hydroxyapatite 100 parts are mixed, 50 parts of Jell-like Paenibacillus liquid is added, the viable bacterial concentration of the Jell-like Paenibacillus liquid used is 10 8 CFU / mL, which is a coal-based solid waste composite material.

[0113] The obtained coal-based solid waste composite material is mixed into 100 times weight of soil for heavy metal contaminated soil remediation.

[0114] Comparative Example 10

[0115] Desulfurization gypsum 500 parts, fly ash 400 parts, wood fiber 200 parts, citric acid 50 parts and hydroxyapatite 50 parts are mixed, 20 parts of Jell-like Paenibacillus liquid is added, the viable bacterial concentration of the Jell-like Paenibacillus liquid used is 108 CFU / mL, i.e. coal-based solid waste composite material.

[0116] The obtained coal-based solid waste composite material is incorporated into 100 times weight of soil for repairing heavy metal contaminated soil.

[0117] Experimental examples

[0118] The soil (not containing heavy metals) incorporated with the coal-based solid waste composite material of Examples 1-5 and Comparative Examples 1-10 is used as a repair base material to repair Cu, As, Cd composite contaminated soil (Cu: 325.04 mg / kg, As: 409.25 mg / kg, Cd: 43.19 mg / kg), and the mixture weight ratio of the repair base material and the soil to be repaired is 1:20, which is placed at room temperature for one week. After one week, the content of Cu, As, and Cd in the repaired soil is detected by X-ray fluorescence spectrometry, and each group of experiments is repeated three times in parallel. The results are shown in Tables 1-3 below:

[0119] Table 1: Heavy metal Cu content detection results (unit: mg / kg)

[0120] Sample 1 Sample 2 Sample 3 Example 1 9.31 9.51 9.95 Example 2 1.24 1.81 1.24 Example 3 9.11 9.04 9.3 Example 4 0.61 1.31 1.09 Example 5 2.98 3.03 2.79 Comparative Example 1 103.12 96.39 104.53 Comparative Example 2 121.52 124.68 112.3 Comparative Example 3 111.48 109.85 111.9 Comparative Example 4 137.02 144.34 146.29 Comparative Example 5 130.98 124.25 124.53 Comparative Example 6 187.69 187.61 183.08 Comparative Example 7 186.44 192.99 195.87 Comparative Example 8 196.96 206.73 201.67 Comparative Example 9 177.13 179.53 177.04 Comparative Example 10 151.24 147.04 151.26

[0121] Table 2: Heavy metal As content detection results (unit: mg / kg)

[0122]

[0123]

[0124] Table 3: Heavy metal Cd content detection results (unit: mg / kg)

[0125]

[0126]

[0127] The determination results show that the coal-based solid waste composite material provided by the examples of the present application can achieve the best soil heavy metal repair effect.

[0128] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled persons in the technical field, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method of soil remediation, characterized in that, The method comprises the following steps: mixing the coal-based solid waste composite material with non-polluted soil to obtain a repair base material; mixing the repair base material with the heavy metal contaminated soil to be repaired to repair the soil; the weight ratio of the coal-based solid waste composite material to the non-polluted soil is 1:50-150; the weight ratio of the repair base material to the heavy metal contaminated soil to be repaired is 1:10-50; the coal-based solid waste composite material is composed of the following components in parts by weight: desulfurized gypsum 500 parts, fly ash 200 parts, wood fiber 200 parts, humic acid 100 parts, sodium silicate 20 parts, EDTA 10 parts, citric acid 10 parts and hydroxyapatite 20 parts; the coal-based solid waste composite material further comprises a microbial agent; the weight of the microbial agent in the coal-based solid waste composite material is 40-60 parts; the microbial agent contains jelly-like Paenibacillus. The viable cell concentration of Paenibacillus jamilae in the microbial inoculant is 10 7 ~ 10 10 CFU / mL.

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